While this basically depends on your actual requirement and preferences, below are some guidelines.
If you are very clear about what exactly you want in the logo (images, the mood you want to convey etc.) then the Basic package would be a good option.
If you do not have clear idea on the mood you want to convey or the images, then the Platinum package may suit you best.
If you have a fairly good idea about the mood you want to convey and/or the images to be present in the logo, go for the Silver or Gold packages; they offer you different number of concepts and variations, choose the appropriate one for you based on how selective you think you are.